A Study on Carotid Arterial Remodeling in patients with Obstructive Coronary Artery Disease and Disease Free Subjects.

INTRODUCTION : Decades of silent arterial wall alterations precede vascular clinical events, which then reflect advanced atherosclerotic disease. The first morphological abnormalities of arterial walls can be visualized by Bmode ultrasonography. This high-resolution, noninvasive technique is one of the best methods for the detection of early stages of atherosclerotic disease, because it is rapidly applicable, readily available and demonstrates the wall structure with better resolution than any other similar technique .Accordingly, ultrasound has been used in a number of studies to monitor the intima-media thickness (IMT) of the carotid arteries, a measurement which has consequently been shown to be associated with cardiovascular risk factors and the incidence of cardiovascular disease. Furthermore, there are diverse approaches for measuring IMT, and some of these may lead to divergent results. Moreover, there are no unified criteria for distinguishing atherosclerosis as seen in early plaque formation from thickening of the intimal-medial complex. This is because IMT reflects not only early atherosclerosis, but also non atherosclerotic compensatory enlargement with largely medial hypertrophy as a result of smooth muscle cell hyperplasia and fibro cellular hypertrophy. This differentiation is important because epidemiological studies have shown that wall thickening as depicted by ultrasonographic measurements of IMT is different from atherosclerotic plaque regarding localization, natural history, risk factors and predictive value for vascular events. As IMT is being increasingly used in clinical trials to serve as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis, it is imperative that standardized methods be used to allow homogenous data collection and analysis. This would help to improve the power of such studies and to facilitate the merging of large databases for meta-analyses. In our study correlation of intima medial thickness with carotid artery remodeling and coronary artery disease status is assessed. AIM OF STUDY : To study the carotid arterial remodeling in patients with coronary artery disease. To study the relationship between carotid arterial inter adventitial and lumen diameters to the intima medial thickness. To evaluate carotid arterial diameters of individuals with coronary artery disease and how it differed from those of CAD-free controls and To study the relationship between carotid artery remodeling and severity of cornary artery disease. CONCLUSIONS : 1. Common carotid atherosclerosis is associated with larger IA diameter and no reduction in lumen diameter POSITIVE REMODELING. Conversely, in the internal carotid, greater IMT is associated with smaller lumina in the absence of IA diameter enlargement. NEGATIVE REMODELING. 2. Case-control comparisons suggest differences in arterial dimensions: common carotid IA diameter was greater in cases than controls, whereas internal carotid lumen and IA diameter were both reduced in CAD cases compared with controls. However, interactive effects of case status on the associations between IMT and arterial dimensions did not reach significance. Patients with triple vessel disease had significant remodeling of carotids when comparing patients with single vessel disease. 3. The data is consistent with the concept that lack of arterial enlargement of the internal carotid during atherosclerosis progression partly explains the well-documented association of this carotid segment with symptomatic cardiovascular disease and the difference in the arterial biologic, physiologic and atherogenic prones properties of the different segments of carotid arteries